TB

Question 1

TB in children vs adults

Answer 1

Children:

• <5yo more likely to have life-threatening TB disease as immunity lower
• and more likely to have disseminated TB (esp. miliary/meningitis)
• more likely to have TB disease from primary infection, vs activation of latent TB in adults
• most are SMEAR NEGATIVE
• rarely infectious: pattern of disease, low bacillary load + lack of coughing force
• unlikely to be index case!

Question 2

TB - type of organism

Answer 2

gram positive obligate aerobe with wax wall

acid fast bacilli

Question 3

which part of the lungs does TB tend to sit in?

Answer 3

upper lobes - obligate aerobe!

Question 4

outline testing options for TB

Answer 4

1. TST preferred for asymptomatic esp <5yo (less reliable <6mo)
   - CI if previous TB or previous large reaction
   - false positive if bcg vax esp early infancy, or NTM exposure
2. QFN-GOLD adolescents

Question 5

interpreting the TST

Answer 5

1. > =5 mm in children who have household contacts
2. > =10 mm in children with history of close contact or endemic area
3. > =15 mm in all other children

Question 6

where might BCG vax scars be?

Answer 6

deltoid, forearm, thigh, scapulae

Question 7

what size/location of LN do you have to expect TB in?

Answer 7

> 1cm in neck, >1.5cm in axilla, >2cm in groin, and do not improve within 1 week of anti-staphylococcal antibiotics

Question 8

clinical spectrum of TB disease - what can it affect?

Answer 8

1. asymptomatic: 80-95% infected children, 40-50% infected infants
2. meningitis
3. eyes
4. pulmonary TB A) primary B) progressive C) chronic
5. pleural effusion
6. pericarditis
7. abdominal
8. kidneys - sterile pyuria
9. bones - ponchet’s (arthritis), pott’s (spine)
10. skin
11. miliary TB

Question 9

what is miliary tb

Answer 9

refers to TB spread haematogenously to >2organs

Question 10

active TB in household contact - what do you do?

Answer 10

If <6mo: TPT whole course > TST at 6mo
If <2yo: TPT wjole course

If <5yo, start TPT regardless

• if initial TST neg: do break of contact repeat TST after 3mo
• — if negative break of contact > consider BCG vax
• if initial TST positive: do whole TPT course

Question 11

main side effect of TPT (aside from non-compliance)

Answer 11

isoniazid-related hepatotoxicity; but this is rare in children and if baseline LFTs are normal, you wouldn’t have to monitor

Question 12

active TB - what do you do now?

Answer 12

1. contact trace
2. notification to gov
3. micrbiological and drug susceptibility testing
4. imaging as required; CXR is a must
5. medications

Question 13

what type of Rx regimens for TB?

Answer 13

non-severe pulmonary or peripheral lymph node TB:
2 months RIP > 4 months RI

if adolescent, HIV positive, or severe child (inc sputum positive TB): add ethambutol to reduce resistance

+/- steroids e.g. severe miiary disease, compressive lymphadenopathy

Question 14

children vs adult TB meds

Answer 14

1. Children require higher mg/kg of antituberculosis drugs to achieve effective serum concentrations
2. Adverse effects rare in children

Question 15

efficacy of BCG vaccine in children

Answer 15

BCG is 70 to 80 percent effective against all forms of TB when administered at birth to mycobacteria-naïve infants

Question 16

what are MDR TB or XDR TB?

Answer 16

MDR TB resistant to R/I
XDR TB resistant to R/I/fluoroquinolone and one of 
1.	Amikacin
2.	Capreomycin
3.	Kanamycin

Question 17

NTM - which do we care about?

Answer 17

mycobacterium avium - causes MAC (+ pulmonary disease)
mucobacterium kansaii - mimics MTB
mycobacterium ulcerans - Buruli ulcer!

Question 18

buruli ulcer - how does it present?

Answer 18

incubation weeks-months

firm painless nodule > weeks > painless necrotic ulcer > OM, lymphoedema

Question 19

treatment for buruli ulcer

thing to tell pts about the treatment

Answer 19

rifampicin + quinolone or clarithromycin 8 weeks

Treatment with antibiotics can sometimes cause a paradoxical inflammatory reaction and enlarging ulceration

Question 20

MAC lymphadenopathy

Answer 20

indolent 
purple 
unilateral 
nontender 
usually <5yo

Question 21

mycobacterium type of granuloma

Answer 21

caseating!

Question 22

two common causes of atypical pneumonia in kids

Answer 22

mycoplasma pneumoniae

chlamydia pneumoniaea

Question 23

afebrile pneumonia of infancy = what bug!

Answer 23

very young, up to 4mo
chlamydia trachomatis
rhinorrhea and tachypnea followed by a staccato cough pattern

Question 24

exam thoughts - what = chlamydia pneumoniae?

Answer 24

atypical pneumonia

often worse than patient’s clinical status: mild , diffuse involvement/ lobar infiltrates

Question 25

how to treat the atypical pneumoniaes?

Answer 25

a. Doxycycline OR azithromycin OR clarithromycin

b. Therapy usually for 7-10 days (except azithromycin which is used for 3-5 days)

Question 26

mycoplasma pneumoniae - key thing to know for exams??

Answer 26

• key associations*
  1) skin: SJS/TEN, EM
  2) neuro: demyelination, ataxia, bell’s, encephalitis
  3) haem: DAT +ve haemolysis, cold Ab mediated disease

1/3 hilar lymphadenopathy
appear worse than the clinical exam

Question 27

mycoplasma pneumoniae - what age group?

Answer 27

school aged children and up

Question 28

what do mycoplasma hominis and urease urealtyicum have in common?

Answer 28

they are the genital mycoplasmas!

Question 29

how can leptospirosis present

Answer 29

1) anicteric 90%, mild no mortality
- initial 3-7d septicaemic: blood only, constitutional sx
- second up to 1mo immune phase: recurrence of fever + aseptic meningitis/uveitis

2) icteric / Weil’s - 15% mortality
- initial septicaemic phase same
- second immune phase much worse: liver (jaundice), renal failure, thrombocytopaenia, CV collapse, haemorrhage